Process for concentrating kainite by means of flotation



Oct. 23, 1962 G. MARULLO ETAL 3,059,773

PROCESS FOR CONCENTRATING KAINITE BY MEANS OF FLOTATION Filed July 6, 1960 s Sheets-Sheet 1 5 4 8 .5 16 T {4 in,

Carbon atoms Oct. 23, 1962 G. MARULLO ETAL 3,059,773

PROCESS FOR CONCENTRATING KAINITE BY MEANS OF FLOTATION Filed July 6, 1960. 3 Sheets-Sheet 2 m m m Amine cansumpfion as hydrochlor ide in grams per fan 0d. 23, 1962 Q TAL' 3,059,773

PROCESS FOR CONCENTRATING KAINITE BY MEANS OF FLOTATION Filed July 6. 1960 3 Sheets-Sheet 3 100 i yields Z K 0 Y 1 ,a m

Hg-grams per liter of saline solution United States Patent 3,059,773 PROCESS FOR CON CENTRATHNG KAINITE BY MEANS OF FLOTATION Gerlando Marullo, Giovanni Perri, and Giuseppe Tubiello, Novara, Italy, assignors to Montecatini, Societa Generale per llndustria Mineraria e Chimica, Milan, Italy, a corporation of Italy Filed July 6, 1960, Ser. No. 41,199 Claims priority, application Italy July 10, 1959 8 Claims. (Cl. 209-166) This invention relates to an improvement in a process quired in the flotation of other potassic ores, for example sylvite, employing the same amines.

We have investigated the floating power of normal, saturated and unsaturated, aliphatic amines having from four to eighteen carbon atoms in the chain, while using saline solutions of the following types:

Grams per liter Types K Na Mg 01 S04 A 7. 32 5. 6 100 280 34. 8 B 14. 7 8. 04 91 250. 7 60. 0 C 26. 3 20.0 75. 210. 2 92.0 D 32. 8 21. 5 61.35 213. 4 66. 85

We found, to our surprise, that amines comprised between C and C have a floating power remarkably higher than others. In particular, for the n-amines C C C the amount required for good flotation is about 5 times lower than that of longer chain-amines, such as C C C It was also found that the floating power of the following amines: C C C C C remains almost constant despite any variance of the composition of the saline solution constituting the turbid liquid, whereas, in contrast it varies markedly for other longer chain-amines. The diagram in FIG. 1 illustrates the variation of the flotation yield as a function of the number of carbon atoms in the amines. On the abscissa are plotted the numbers of carbon atoms of the amines, and on the ordinate are the yields in percent K 0. This diagram indicates that a maximum floating power corresponds to the following normal amines: C C C The tests referred to on this diagram were carried out by maintaining constant the consumption of the amine collector and the composition of saline solution.

The curves in FIG. 2 show the variation of flotation yield as a function of the consumption of the collector, for various amines. On the abscissa is plotted the amine consumption, as hydrochloride, in grams per ton of kainite ore, "and on the ordinate'is plotted the yield in percent K 0. From this diagram it is evident that the amines C C C have the highest floating power, and their consumption, other conditions being equal, is about 5 times lower than longer chain-amines (C C C The diagram in FIG. 3 shows, as an alternative, the influence of the composition of saline solution upon the floating power of the amines. On the abscissa are plotted the Mg contents in grams per liter of the solutions indi- 3,059,773 Patented Oct. 23., 1962 cated in the table in column 1, and on the ordinate the yields in percent K 0.

From this diagram it is evident that floating powers of these shorter chain amines, and among them C C C remain almost unvaried upon varying the composition of saline solution.

FIGS. 1, 2, 3 and the following of an illustrative character presented without intent to limit the present invention, show synthetically the results obtained by the tests.

From these results, it now becomes evident that, by employing in the kainite flotation, aliphatic amines having nine and ten carbon atoms, the process is very much more economical, and more suited to the ore pulp liquid.

The amine consumption of gr./ton, as indicated in the examples, relates to the use of freshly prepared saline solutions. In industrial practice, such consumption is greatly reduced by recycling the solutions which contain amine dissolved therein.

In the following examples kainite mineral having the following composition was employed:

K O=l2.5%; Na=12.6%; Mg=6.45%; Cl=28.85%-

Insoluble in water =0.5%; SO +H O=at 100 The mineral was ground is tabulated as follows, the cent departure from 1 mm. size:

to 1 mm. The granulometry mm. I mm. Percent This mineral was suspended in one of the solutions referred to in the table found in column 1, so as to make an ore pulp comprising 35% by weight of solid. After the amine collector was added in the form of hydrochloride, the solution was conditioned for three minutes. Then 80 grams per ton of cyclohexanol were added as foaming substance, and flotation was carried out according to the known technique in a small laboratory cell having a 2-liter useful capacity.

Examples 2, 3, 4 :and 5 employ the longer chain amines, being presented for comparison with Examples 1, 6, 7, 8. In the latter, the yield of K 0 in the floated mineral is markedly superior.

EXAMPLE 1 Kainite mineral 1000 gr. Type C solution 1500 cc. n-Primary decylamine (in form of hydrochloride) 80 gr./ton. Cyclohexanol 80 gr./ton. Balance:

KO, Y Product Weight Peritent Pei'i iit 1,000 12.5 V 700 17 res1due.- 340 1175 examples, which are figures signifying weight per-.

3 EXAMPLE 2 According to Example 1, but using primary n-hexadecylamine hydrochloride, instead of the decylarnine.

Balance:

K20, Yield,

Product Percent Percent Raw mineral 1,000 12. 5 floated 285 17.5 residue 765 9. 8

EXAMPLE 3 Balance:

K10, Yield, Product Weight Percent Percent Raw mineral 1, 000 12. 5 floated 390 17. 5 54. 5 residue 665 8. 58

EXAMPLE 4 Type A solution 1500 cc. n-Hexadecylamine (as hydrochloride) 80 gr./ton.

The rest according to Example 1.

Balance:

K10, Yield, Product Weight Percent PeKrcent Raw mineral 1,000 12. 5 floated 202 17. 2 as residue 798 10.

EXAMPLE Type D solution 1500 cc. n-Hexadecylamine (as hydrochloride) 80 gr./ton.

The rest according to Example 1.

Balance:

K 0, Yield, Product Weight Percent Perceont 1,000 12.5 475 17.4 66 residue. 565 7. 5

EXAMPLE 6 Type A solution 1500 cc. n-Decylamine (as hydrochloride) 80 gr./ton.

The rest according to Example 1.

Balance:

K10, Yield, Product Weight Percent Percglt Raw mineral 1,000 12. 5 710 16.8 05.5 residue 330 1. 52

4 EXAMPLE 7 Type C solution 1500 cc. n'Undecylene-amine (as hydrochloride) gr./ton. The rest according to Example 1.

Balance:

K10, Yield, Product Weight Percent Percgnt 1,000 12.5 708 17.0 residue. 334 1. 5

EXAMPLE 8 Type C solution 1500 cc. Mixture of amines constituted of 30% n-nonyl, 35% n-decyl, 35% n-undecyl 80 gr./ ton. as hydrochloride. The rest according to Example 1.

Balance:

K10, Yield, Product Weight Percent Percgit Raw mineral 1,000 12. 5 floated 705 16.9 5 residue 342 1. 6

The analyses were carried out using filtered and dried products. The overweight of the products with reference to the weight of the starting mineral is due to the salts from the saline imbibing solution.

We claim:

1. In a process of concentrating kainite by froth flotation, in which a suspension is formed of comminuted kainite containing material in saline water containing a frothing agent, the improvement comprising adding to the water at least one compound of the group consisting of normal primary aliphatic amines of the formula R-NH in which R is a hydrocarbon radical having from 8 to 11 carbon atoms and is taken from the group consisting of alkyl and alkenyl radicals, and salts thereof with mineral acids.

2. In a process of concentrating kainite by froth fiotation, in which a suspension is 'formed of comminuted kainite containing material in saline water containing a frothing agent, the improvement comprising adding to the water at least one compound of the group consisting of normal primary aliphatic amines of the formula R-NH in which R is a hydrocarbon radical having from 8 to 11 carbon atoms and is taken from the group consisting of alkyl and alkenyl radicals, and salts thereof with mineral acids, the saline solution containing positive and negative ions of the group consisting of K, Na, Mg, Cl, S0

3. The process defined in claim 2, the frothing agent being cyclohexanol.

4. The process defined in claim 2, the amine being normal decylarnine.

5. The process defined in claim 2, the amine being normal nndecylene amine.

6. The process defined in claim 2, the amine being normal nonyl amine.

7. The process defined in claim 2, the amine being normal undecyl amine.

8. The process defined in claim 1, the compound being an amine hydrochloride.

References Cited in the file of this patent 

1. IN A PROCESS OF CONCENTRATING KAINITE BY FROTH FLOTATION, IN WHICH A SUSPENSION IS FORMED OF COMMINUTED KAINITE CONTAINING MATERIAL IN SALINE WATER CONTAINING A FROTHING AGENT, THE IMPROVEMENT COMPRISING ADDING TO THE WATER AT LEAST ONE COMPOUND OF THE GROUP CONSISTING OF NORMAL PRIMARY ALIPHATIC AMINES OF THE FORMULA R-NH2 IN WHICH R IS A HYDROCARBON RADICAL HAVING FROM 8 TO 11 CARBON ATOMS AND IS TAKEN FROM THE GROUP CONSISTING OF ALKYL AND ALKENYL RADICALS, AND SALTS THEREOF WITH MINERAL ACIDS. 